Interesting Clam behavior

[04scoobysti]

So i've had my 5" Crocea for about 8 months now and in the past month or so it had started moving. The clam is very healthy, great extension, quick to react, no gaping.

Its is attached a rock but it has been slowly moving away from it and closer to the glass. I haven't touched it or tried moving it back to where it was because i figure the clam will do what's best for itself. Just today i noticed it has expelled some byssal matter, now i know this is done just as a matter of necessity and isn't unhealthy, but its still hard not to touch the clam or try to move it to get a better look at the foot (or whats left of it).
I'm just waiting for my camera to charge up and i'll post a picture of the expelled matter i'm referring to. Just thought i would share this and to see if anyone else has seen this behavior before.